Process and apparatus for spinning bicomponent micro-denier fibers



H. s. WOODBERY 3,358,322 PROCESS ANDAPPARATUS FOR srmmuu BI-COMPONENT MICRO-DENIER FIBERS 2 Sheets-Sheet 1 Dec. 19, 1967 Filed June 10, 1965 S. WOODBERY PROCESS AND APPARATUS FOR SPINNING BI-COMPONENT MICRO-DENIER FIBERS Dec. 19, 1967 2 Sheets-Sheet 2 Filed June 10, 1965 FIG.4.

INVENTOR. HUNTER S. WOODBERY BY 2 p ATTORNEY United States Patent 3,358,322 PROCESS AND APPARATUS FOR SPINNING BI- COMPONENT MICRO-DENIER FIBERS Hunter S. Woodbery, Decatur, Ala., assiguor to Monsanto Company, St. Louis, M0., a corporation of Delaware Filed June 10, 1965, Ser. No. 462,898 8 Claims. (Cl. 182.5)

This invention relates to a method and apparatus for producing conjugate micro-denier synthetic fibers and more particularly relates to the use of a rotating cone spinnerette for producing conjungate micro-denier synthetic fibers.

Natural staple fibers such as wool have an inherent curl or crimp which impart to them certain desirable characteristics. For example such a crimp provides resistance to longitudinal movement relative to adjacent fibers and hence is productive of a yarn having good tensile strength. Due to the nature of the method of spinning, man-made fibers do not have a natural crimp and such must therefore be artificially introduced.

Several methods are utilized for introducing a crimp to man-made fibers. One method is to pass a heated tow of filaments between a pair of meshed gears to permanently bend or crimp them. Another method is the use of a conjugated filament. In the latter, a. plurality of filaments spun from solutions that will produce fibers having different shrinkage characteristics are spun together to form a single bi-component filament. When heated, as in an annealing step, such a bi-component filament will curl or kink into a crimped fiber.

The conjugate filament method of introducing a crimp to man-made fibers of the more usual deniers has been utilized in various forms for some time. It has, however, not been heretofore possible to produce conjugate filaments Where micro-fibers are produced by a process generally referred to as centrifugal spinning. In this process, a fiber-forming material is introduced onto the surface of a rotating cone-shaped spinning element. The rotating material is moved to the edge of the cone by centrifugal force and slung in thin streams or droplets into a path of high-velocity air directed toward a collecting screen where it is deposited as a fibrous batt. During travel from the cone to the collecting screen, the fiber forming material is changed into a plurality of fibers having diameters from 0.5 to 25 microns or, as they are commonly known, micro-fibers or micro-denier fibers.

In one embodiment of the instant invention, two spinning solutions are combined on the surface of the rotating cone by means of concentric supply passages and travel together as bi-component filaments to the collecting screen along the route previously described. Other embodiments of the invention utilize a chamber at the outlet end of the solution supply system within which one of the solutions is superimposed on the other to provide a bi-component solution on the surface of the rotating cone which, as explained above, will be collected on a screen as a conjugate filament.

Accordingly, it is an object of the invention to provide a method and apparatus for producing conjugate microfibers.

Another object of the invention is to provide a method and apparatus for producing conjugate micro-fibers utilizing rotating cone spinning.

A further object of the invention is to provide a method and apparatus for producing conjugate micro-fibers utilizing the rotating cone spinning method in which the components travel across the face of the cone together.

These and other objects and advantages of this invention will be more apparent upon reference to the following specification, appended claims and drawings wherein:

3,358,322 Patented Dec. 19, 1967.

FIGURE 1 is a partly sectional side view of microdenier fiber rotating cone spinning apparatus according to the instant invention;

FIGURE 2 is a cross-sectional detailed view of the rotating cone spinning member according to one embodiment of the instant invention;

FIGURE 3 is a view similar to FIGURE 2 but showing another embodiment of the cone spinning member; and

FIGURE 4 is a view similar to FIGURES 2 and 3 showing still another embodiment of the cone spinning member.

In order to better understand the construction and use of this novel device, it will be described in relation to the production of conjugate fibers. It is to be understood, however, that various other uses may be found for this novel filament spinning apparatus. For example, one component could consist of the more usual material while the second component could be any of a number of substances such as water, air, pigment, a slurry of magnetic particles and solvent, and others obvious to those skilled in the art.

With continued reference to the accompanying figures wherein like numerals designate similar parts throughout the various views, and with initial attention directed to FIGURE 1, reference numeral 10 designates generally apparatus for producing conjugate micro-fibers according to the invention. Reference numeral 12 designated generally spinning apparatus for converting a plurality of spinning solutions into fibers while reference numeral 14 denotes a mechanism for collection of the fibers.

The spinning apparatus 12 includes a distributing element 16 rotatably mounted in a supporting collar 18. One end of the distributing element 16 is flared outward to form a cone-shaped portion 20 while the other end 22 is secured to a pulley 24 which is driven through a belt 26 by an electric motor 28. Obviously, the rotary output of the motor 28 is translated into a like movement of the distributing element 16 around an axis of rotation passing through the element and determined by the position of the supporting collar 18.

Two separate sources of spinning solutions mixed with a suitable solvent are illustrated diagrammatically at 30 and 32. These solutions are caused to flow through tubes 34 and 36 or other suitable supply means by pumps 33 and 40 into the end 22 of the distributing element 16. As the tubes 34 and 36 enter the distributing element 16, they are formed concentrically as shown at 42 to maintain solution separation well into the interior of the element 16 for a purpose to hereinafter be more fully explained.

A manifold 44 surrounds the distributing element 16 proximate the outermost edge of the cone-shaped portion 20. Air or any other suitable gas or fluid is supplied at an elevated temperature to the manifold 44 through a heat exchanger 46 by a centrifical blower 48. A plurality of bafiles serve to distribute the air evenly around the edge of the element 16 and direct it toward the collecting mechanism 14 through an enclosure formed by walls 52.

An endless, moving screen 54 extending across the enclosure between a pair of rollers 56 (only one of which is shown) intercepts the fibers as they pass through the enclosure toward an exhaust vent 58. As the fibers collect on the screen, a relatively thick batt is found at a point opposite the spinning apparatus 12. Inasmuch as the screen is continuously moving under the influence of the motor 60 driving the roller 56, the batt is formed into an elongated fabric-like web 62 which is separated from the screen 54 and wound on a take-up roll 64 driven by motor 66.

Details of the distributing element 16 are shown in FIGURES 2, 3, and 4 illustrating three embodiments of the invention. In all emodiments element 16 includes a body portion 66 secured through a flange 68 to a flange 70 on the cone-shaped portion 20. An opening 72 extends through the center of the body portion 66 and communicates with an enlarged annular chamber 74 formed in the cone-shaped portion 20. An outwardly flared aperture 75 provides a passageway from the chamber 74 to a face 78 generated on the cone-shaped portion 20 as the outer surface of a right circular cone with its apex cut away by the aperture 76 and the periphery of the base at its outer edge 80.

The axis of symmetry of the face 78, the cone-shaped portion 20 andthe body portion 66 all coincide with the longitudinal center lines of the chamber 74 and the opening 72 which, if extended, would also coincide. As stated before, the distributing element 16 is rotatably mounted. The mounting, including bearing members 82 and 84, is arranged so that the axis of rotation of the element 16 also coincides with the lines and axes described above.

Tube 34 extends through and is centrally located in the opening 72 in all of the embodiments illustrated in FIGURES 2-4. The tube 34 extends into the chamber 74 which is isolated from the opening 72 by a ringshaped seal 86 closely fitted into a recess 88 in the body portion 66. Obviously, as the distributing element rotates, the tube 34 remains stationary with its outer surface sliding relative to the seal 86. If desired the tube 34 can be eliminated and the opening 72 used to supply one of the spinning solutions.

In the embodiment illustrated in FIGURE 2, tube 36 extends concentrically through tube 34 and terminates within a cavity 90 formed in a dispensing member 92 mounted in the chamber 74. A ring-shaped seal 94 tightly fitted to a wall of the cavity 90 prohibits the intermixing of the solution present in the cavity 90 with the solution found in the chamber 74, but will rotatably slide across the outer surface of the tube 36 so that the tube 36 remains stationary as the element 16 rotates.

A portion 96 of the dispenser 92 extends through the aperture 76 and is curved along its outer face 98 so as to be spaced everywhere equidistant from the surface of the aperture 76 and face 78 to form an outlet 100 from the chamber '74 to the face 78. A passageway 102 having a surface 104 curved so as to intercept the outer surface 98 at a point 106 extends outwardly from the cavity 90.

The dispenser 92 is held in position by a disc-shaped mounting member 108 press fitted, welded, brazed or otherwise suitably secured both to the outer wall of chamber 74 and in a recess 110 on the exterior surface of the dispenser. A plurality of passageways 112 are provided in the mounting member 108 in order that the flow of spinning solution through the chamber 74 will not be materially impeded.

In the embodiment illustrated in FIGURE 3, the tube 36' passes concentrically through tube 34 similarly to tube 36 in FIGURE- 2 but is curved at its outer end 114 to direct one of the spinning solutions outwardly at a 90 angle from the axis of rotation of the distributing member 16 toward the outer wall of the chamber 74.

A similar result is obtained in the embodiment illustrated in FIGURE 4 by the use of a pair of baflles. A first bafiie 118 is secured to the body portion 66 by suitable fastening elements 120 such as, for example, a threaded bolt, across the open mouth of the tube 34. A second baifle 122 is disposed across the mouth of the tube 36" and secured to the first baffle 118 by suitable fastening elements 124.

As best shown in FIGURE 4, the tube 34 extends only a short distance into the chamber 74 before terminating in a mouth closely spaced to the first baffie 118. The tube 36" extends into and through the baffle 118 almost to the outermost extent of chamber 74 before terminating and, again, a small clearance is provided between its month and the baffle 122. Obviously, bafiles 118 and 122 may have any suitable configuration but are preferably circular, solid discs symmetrical about the axis of rotation of the distributing element 16. As illustrated, the diameter of the bafiie 118 is slightly greater than the diameter of the aperture 76 while the diameter of the bafiie 122 is slightly less so that a spinning solution pumped through tube 34 will form a reservoir in the chamber 74 overlaid by solution forced through tube 36". Other baffle to bathe and baffle to aperture size relationships may be utilized as long as a smooth flow of material and a uniform overlay is maintained.

In forming a conjugate micro-fiber utilizing the apparatus shown in FIGURE 2, the distributing element 16 is rotated at a high speed and a first spinning solution is caused to flow through the tube 34 into the chamber 74, through passageway 112 and the outlet 100 onto the face 78' where it spreads into a thin film under the influence of the stresses caused by the rotary motion. Similarly, a second spinning solution having shrinkage characteristics differing from those of the first is forced through the passageway 102 onto the curved face 104 where it also spreads as a thin film. At point 106 the two films join into a bi-component liquid film which moves across the face 78 to the edge Where it is slung into the stream of heated air emitted from the manifold 44. The air stream evaporates the solvent causing a bi-component micro-fiber to be formed which, as it is heated, will curl to a crimped or textured fiber. As described before the stream of air also carries the fibers to a collecting screen 54.

Conjugate micro-fibers are formed by the apparatus of FIGURE 3 in the following manner. A first spinning solution is introduced into the chamber 74 through the tube 34 and due to the rotary motion of the distributing element 16 forms a toroidal shaped reservoir 116 which will overflow through the aperture 76 and spread as a thin film across the face 78 as more solution is pumped in. At the same time a second spinning solution is spread on the surface of the reservoir through tube 36 in a thin film and is carried through the aperture 76 on the surface of the first spinning solution as it spreads onto the face 78. Thus, a bi-component film is formed which when slung from the edge 80 is converted into conjugate microfibers in the manner described above in connection with FIGURE 2.

Similarly to the apparatus illustrated in FIGURE 3, in the embodiment illustrated in FIGURE 4, a first spinning solution is introduced into the chamber 74 through the tube 34 and due to the rotary motion of the distributing element 16 forms a toroidal shaped reservoir 116. The second spinning solution is introduced into the chamber 74 through the tube 36". In this embodiment, however, the first solution emerges from the tube 34 and spreads, under the influence of rotary motion, across the baflie 118 and into the reservoir 116. The second solution emerges from the tube 36" onto the surface of the bafiie 122 and spreads outwardly to forman overlay on the surface of the reservoir 116. As the reservoir 116 overflows through the aperture 76 it carries the second solution on its surface and both spread as a thin film across the face 78. Again, a bi-component film is formed which when slung from the edge 80 is converted into conjugate microfibers in the manner described above. These baffles 118 and 122 act to transfer the first and second spinning solutions to the reservoir 116 and as an overlay on the reservoir respectively, with a minimum of turbulence, and thus, prevent intermixing.

A practically infinite number of combinations of rotational speeds, solution flow rates and air flow rates can be utilized with the apparatus of the invention to achieve the desired spinning performance. Thus, fiber denier, degree of crimp and other characteristics can be varied as required.

It will be apparent that there has been herein disclosed a method and apparatus for producing conjugate microdenier fibers using a spinning cone, an accomplishment not heretofore possible. Thus, it will now be practical to produce on a large scale, relatively inexpensive, high quality, textured fibers in the micro-denier range.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. An apparatus for spinning conjugate micro-fibers comprising a frame; a hollow frustoconical member rotatably mounted on the frame and having therein a circular central opening, means for rotating said member about its axis, said member having in communication with the central opening thereof an annular chamber having a diameter greater than the diameter of said central opening for receiving a spinning solution, said solution being held in the chamber by centrifugal force when said member is rotated, a pair of inlet lines extending through said central opening for feeding two different spinning solutions through said opening and into said chamber, said spinning solution overflowing from said chamber outward through the central opening and onto the inner face of said frustoconical member, and means surrounding said member for directing a stream of heated air past said member to carry away fibers formed by rotation of said member.

2. The apparatus of claim 1 wherein each of the inlet lines is provided with a baflie spaced from the end of said line for directing the spinning solution outward into said chamber.

3. The apparatus of claim 1 wherein the apparatus is provided with a dispenser mounted in said chamber, said dispenser having therein a cavity, one of said inlet lines terminating in said cavity to feed one of the spinning solutions thereto, said dispenser having a conical central opening for feeding said one spinning solution outward onto said frustoconical member, said dispenser being spaced from the wall of said circular central opening to allow the other solution to flow therebetween from the chamber.

4. The apparatus of claim 3 wherein the conical central opening of the dispenser is formed by a hollow frustoconical element.

5. The apparatus of claim 3 wherein the cavity is annular in configuration, said annular cavity having a diameter greater than the diameter of the central opening in said dispenser.

6. Apparatus according to claim 1 in which one of said inlet lines terminates within a cavity in a dispenser mounted in said chamber.

7. Apparatus according to claim 1 in which one of said inlet lines terminates in said chamber in a curved portion directed toward the outer wall of the chamber.

8. Apparatus according to claim 1 in which a baflie is spacedly mounted across the mount of each of said inlet lines for directing the spinning solution toward the outer wall of said enlarged chamber with a minimum of turbulence.

References Cited UNITED STATES PATENTS 2,880,456 4/1959 Kuzela et al l82.5 2,931,422 5/1960 Long 18-25 X 2,998,620 9/1961 Stalego 182.5 X 3,015,128 1/1962 Somerville 182.6 3,097,085 7/1963 Wallsten 18-25 X 3,174,182 3/1965 Duncan 182.5

WILLIAM J. STEPHENSON, Primary Examiner, 

1. AN APPARATUS FOR SPINNING CONJUGATE MICRO-FIBERS COMPRISING A FRAME; A HOLLOW FRUSTOCONICAL MEMBER ROTATABLY MOUNTED ON THE FRAME AND HAVING THEREIN A CIRCULAR CENTRAL OPENING, MEANS FOR ROTATING SAID MEMBER ABOUT ITS AXIS, SAID MEMBER HAVING IN COMMUNICATION WITH THE CENTRAL OPENING THEREOF OF AN ANNULAR CHAMABER HAVING A DIAMETER GREATER THAN THE DIAMETER OF SAID CENTRAL OPENING FOR RECEIVING A SPINNING SOLUTION, SAID SOLUTION BEING HELD IN THE CHAMBER BY CENTRIFUGAL FORCE WHEN SAID MEMBER IS ROTATED, A PAIR OF INLET LINES EXTENDING THROUGH SAID CENTRAL OPENING FOR FEEDING TWO DIFFERENCE SPINNING SOLUTIONS THROUGH SAID OPENING AND INTO SAID CHAMBER, SAID SPINNING SOLUTION OVERFLOWING FROM SAID CHAMBER OUTWARD THROUGH THE CENTRAL OPENING AND ONTO THE INNER FACE OF SAID FRUSTOCONICAL MEMBER, AND MEANS SURROUNDING SAID MEMBER FOR DIRECTING A STREAM OF HEATED AIR PAST SAID MEMBER TO CARRY AWAY FIBERS FORMED BY ROTATION OF SAID MEMBER. 